Lack of interference in long-term memory for socially learned food preferences in rats (Rattus norvegicus)

Outside the laboratory, rats (Rattus norvegicus) are likely both to interact with several conspecifics that have eaten various foods and to eat a variety of foods themselves before they encounter any particular food for which they have a socially enhanced preference. Here the authors examine the stability of rats' socially learned food preferences following 6 days of potentially disruptive ingestive experiences. The authors found that 6 days of (a) eating unfamiliar foods, (b) interacting with demonstrators that had eaten unfamiliar foods, or (c) both eating unfamiliar foods and interacting with demonstrators that had eaten those foods had no measurable effect on rats' socially learned food preferences. The stability of socially enhanced food preferences over time and despite potentially disruptive experiences is consistent with the view that social learning about foods is an important determinant of the food choices of free-living Norway rats.     

Maternal structure and autonomy support in conversations about the past: contributions to children's autobiographical memory

The authors examined the contributions of maternal structure and autonomy support to children's collaborative and independent reminiscing. Fifty mother-child dyads discussed past experiences when the children were 40 and 65 months old. Children also discussed past events with an experimenter at each age. Maternal structure and autonomy support appeared as 2 distinct and separable components of mothers' reminiscing style and acted in an additive fashion to predict children's memory. Children whose mothers demonstrated both high structure and high autonomy support provided the greatest memory in these conversations, whereas children whose mothers were low on both dimensions provided minimal memory. The authors discuss the implications of these effects for children's autobiographical memory development.     

Children's, adolescents', and young adults' reward allocations to hypothetical siblings and fairness judgments: effects of actor gender, character type, and allocation pattern

The authors studied the reward allocation patterns, reasoning, and fairness judgments of 112 participants at 4 grade levels: kindergarten, 3rd grade, 9th grade, and college. Three story characters (an oldest, the most productive, and the physically disadvantaged) were depicted as siblings of the same gender, either sisters or brothers, who poured lemonade at a school picnic. Kindergartners' pattern of reward allocations indicated the use of an equality and productivity-based equity rule, whereas most of the older participants integrated considerations of both productivity and physical disadvantage in their allocations. Reasoning data were generally consistent with the allocation patterns. Reward allocations differed significantly by the gender of the characters, and fairness ratings differed significantly by the gender of the characters and the gender of the participant. Conclusions discuss the increasing coordination and consideration of more than one claim to the reward with development.     

Selective target processing: perceptual load or distractor salience?

Perceptual load theory (Lavie, 1995) states that participants cannot engage in focused attention when shown displays containing a low perceptual load, because attentional resources are not exhausted, whereas in high-load displays attention is always focused, because attentional resources are exhausted. An alternative "salience" hypothesis holds that the salience of distractors and not perceptual load per se determines selective attention. Three experiments were conducted to investigate the influence that target and distractor onsets and offsets have on selective processing in a standard interference task. Perceptual load theory predicts that, regardless of target or distractor presentation (onset or offset), interference from ignored distractors should occur in low-load displays only. In contrast, the salience hypothesis predicts that interference should occur when the distractor appears as an onset and would occur for distractor offsets only when the target was also an offset. Interference may even occur in highload displays if the distractor is more salient. The results supported the salience hypothesis.     

Adult shyness: the interaction of temperamental sensitivity and an adverse childhood environment

This article examines the relation between adult shyness and sensory-processing sensitivity and posits a new model in which the interaction of sensitivity and adverse childhood environment leads to negative affectivity (with the highly sensitive being more impacted), which in turn leads to shyness. Consistent with this model, two questionnaire studies (Ns = 96 and 213) supported three hypotheses: (a) sensory-processing sensitivity interacts with recalled quality of childhood parental environment to predict shyness, (b) sensory-processing sensitivity interacts in the same way with childhood environment to predict negative affectivity, and (c) the interaction effect on negative affectivity mediates the effect on shyness. Hypothesis 2 was tested and supported in an additional questionnaire study (N = 393) and also in an experiment (N = 160) that manipulated negative contemporaneous experience as an analog for adverse childhood environment.     

Perception without awareness: further evidence from a Stroop priming task

In the present research, we examined the influence of prime-target stimulus onset asynchrony (SOA) on Stroop-priming effects from masked words. Participants indicated the color of a central target, which was preceded by a 33-msec prime word followed either immediately or after a variable delay by a pattern mask. The prime word was incongruent or congruent with the target color on 75% and 25% of the trials, respectively. The words followed by an immediate mask produced reliable Stroop interference at SOAs of 300 and 400 msec but not at SOAs of 500 and 700 msec. The words followed by a delayed mask produced a reversed (i.e., facilitatory) Stroop effect, which reached significance at an SOA of 400 msec or longer, but never at the shorter 300-msec SOA. Such an differential time course of both types of Stroop priming effects provides further evidence for the existence of qualitative differences between conscious and nonconscious perceptual processes.     

Age differences and the identity negative priming effect: an updated meta-analysis

A recent meta-analysis (P. Verhaeghen & L. De Meersman, 1998a) revealed that older adults show a reliable but significantly reduced negative priming effect compared with young adults. The present study provides an updated quantitative review on the effect of aging on the magnitude of the negative priming effect in identity tasks. This analysis demonstrated that the negative priming effect was not significantly different between young and old adults. This result differs from P. Verhaeghen and L. De Meersman's study. The implications of this finding for inhibitory-based theories of cognitive aging are discussed.     

The crucial roles of stimulus matching and stimulus identity in negative priming

Negative priming refers to the situation in which an ignored item on an initial prime trial suffers slowed responding when it becomes the target item on a subsequent probe trial. In this experiment (and a replication), we demonstrate two ways in which stimulus consistency (matching) governs negative priming. First, negative priming for identical words occurred only when the prime distractor changed color when it became the probe target (i.e., constant cue to read the red word); negative priming disappeared when the prime distractor retained its color as the probe target (i.e., cue switches from read the red prime word to read the white probe word). Second, negative priming occurred for identical words, but not for semantically related words, whether related categorically or associatively. This pattern of results is consistent with a memory retrieval account, but not with an inhibition account of negative priming, and casts doubt on whether there is semantic negative priming for words.